Re: Starting a program from a command line versus clicking an icon.

Michael Schuh <michael.schuh@xxxxxxxxx> wrote:
> walt <wa1ter@xxxxxxxxxxxxx>:
> > I've written a little C program named rlc which generates
> > random color strings like 'rgb:a5/b3/f1' which I can use
> > like this to start xterm:
> >
> > xterm -bg `rlc` (gives a random-light-colored background)
> >
> > This works great when I type the command from an xterm
> > window -- but it fails when I click on a gnome or xfce
> > icon containing the same command.
> >
> > Any idea why those two methods of starting a program
> > don't produce the same result?
>
> my first shot (not really tested, but my goldfinger say's :-D)
> the backquotes around rlc......
Right. When typed in an xterm, the line is parsed by the
shell, including the backticks which are special syntax of
a shell. I don't use gnome, but I guess it doesn't pass
the command to a shell for execution, but just uses execve()
or similar.
> to workaraund you can try little shell-script.
>
> ----8<-----
> #!/bin/sh
> xterm -ls +sb -bg `rlc` $@
> ---->8----
May I improve on that a bit?
#!/bin/sh -
exec xterm -ls +sb -bg `rlc` "$@"
The "exec" prevents a useless shell process hanging around
until the xterm exits, and the quotes around "$@" are
required to make it work correctly with arguments that
contain spaces. Without quotes, $@ and $* behave the same.
Personally, I also use "-sl 10000" to get 10,000 lines of
scrollback history. My xterm wrapper script also sets the
font size depending on the display width, so I can fit two
xterms (with 80 columns each) beside each other.
Best regards
Oliver
PS: For those interested, this is my xterm wrapper script:
#!/bin/sh -
if [ -z "$DISPLAY" ]; then
echo "Sorry, \$DISPLAY is not set."
exit 1
fi
WIDTH=$(xwininfo -root | awk '/Width:/{print $2}')
if [ -z "$WIDTH" ]; then
echo "Sorry, my \$DISPLAY doesn't work ($DISPLAY)."
exit 1
fi
if [ $WIDTH -gt 1440 ]; then FONT=9x15bold
elif [ $WIDTH -gt 1280 ]; then FONT=8x13bold
elif [ $WIDTH -gt 1120 ]; then FONT=7x13bold
elif [ $WIDTH -gt 960 ]; then FONT=6x13
else FONT=5x8 # Ugh!
fi
exec /usr/X11R6/bin/xterm -fn "$FONT" -sl 10000 "$@"
--
Oliver Fromme -- Bunsenstr. 13 -- 81735 Muenchen -- Germany
``All that we see or seem is just a dream within a dream.''
(E. A. Poe)